Final Project Proposal 2020¶
Fab Speaker Bestial¶
Pixars LuxoJR model adapted from Daniel Bulls thingiverse model
My final project, still unnamed, will be a networked audio speaker. The project follows two avenues.
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The main focus will be on producing an electronic board that will enable connecting a bluetooth emitting device to a speaker for audio playback; that board will connect to other units in range and synchronize the playback, either through bluetooth or wifi.
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The second focus will be on the aesthetic, acoustic and technical aspect of the speaker enclosure, which is open-ended; I will propose one or more enclosures and technical options as I progress with my research on the subject, but each should be compatible with the electronics element.
What will it do?¶
- The final product will play music with reasonably good audio quality.
- Work in a multiple speaker setup.
- Work either with battery or DC input, depending on desired application.
- It shall have a volume knob with on-off switch and have provision for a motion sensor.
- Should be aesthetically pleasing and simple to use.
Large version here
Who has done it before?¶
Matt Keeter’s Fab Boombox has inspired me and is partially what I intend to do, except that my project’s input is bluetooth based and shouldn’t need much in terms in local interaction other than volume control.
Sonos and other commercial solutions are also an inspiration, but they focus too heavily on their closed ecosystem. Sonos’ products work on wifi only, which I find limiting.
Vedran´s Hackaday.io project was also of great interest to me as he proposes using ESP32 which is what I was considering, and it also tackled some of the issues I’m sure to find later on, such as using a higher bitrate DAC than the 8 bit one on the ESP32, and designing a good quality amplifier.
Picoaudio is also an interesting OpenSource project that gave me information as to what components to consider for my project
I have been following Peter Kulicki’s HexiBase website and youtube channel, as his 3d printed sub enclosure and general audio explanation videos are of interest to me and applicable in this project.
What will I design?¶
I will design the electronics, software implementation, user experience, enclosure and acoustic characteristics
What materials and components will be used?¶
The electronics will be ESP32 based because it already has bluetooth and wifi. There will be a DAC chip which I hope to be able to program adapt to the particular acoustic measurement of the audio drivers I will use, and an amplifier designed for adequate output from the drivers in their enclosure. I will design a battery charging circuit as well as provide the adequate DC input.
For the enclosure I will probably iterate several 3d printed models, hoping to cast a final resin model when design is finalized, or whatever production method I find more adequate for the different parts of the enclosure. Some will probably be CNC machined.
Materials, where will they come from, how much will they cost?¶
| Qty | Description | Price | Link | Notes |
|---|---|---|---|---|
| 1 | Full Range driver | 200.00 € | Sound Imports | or salvaged |
| 1 | Woofer | 70.00 € | Sound Imports | |
| 1 | Exciter | 30.00 € | Sound Imports | |
| 10 | ESP32-DEVKITC-32U | 91.10 € | DigiKey | Already have one |
| 10 | MAX98306ETD+T Audio Amp | 11.99 € | DigiKey | |
| 10 | PCM1862DBTR 24BIT DAC | 24.26 € | DigiKey | |
| 10 | Logarithmic Potentiometer with Switch PTR902-2015K-A104 | 25.50 € | DigiKey | |
| 3 | 3d Filament | 90.00 € | fablab | |
| 1 | Other electronics components | fablab |
What parts and systems will be made?¶
- Electronics board, consisting of some ready made parts and as many discrete circuits as I can accomplish
- Aesthetic and acoustically adequate enclosure
- Programming to best of my ability of the necessary modules for full functionality
What processes will be used?¶
- Electronics manufacturing and cycle testing
- Software programming for best operation
- Enclosure and stand design, considering acoustic orders, ergonomics and aesthetics
- Documentation for open sourcing
What questions need to be answered?¶
- Can bluetooth 5 multicast for more than two speakers, if so, how?
- Will wifi have be used for this effect, if so how?
- Can I develop a way for speakers to sync?
- Can I actually accomplish it?
How will it be evaluated?¶
- Through video demonstration and documentation